A number of phosphates and phosphorothioates were described by Rigterink in U.S. Pat. No. 3,244,586. Such compounds are particularly useful as insecticides and biocides. They are represented by Formula I. ##STR1## wherein R represents halopyridyl, Z represents oxygen or sulfur and each R' independently represents lower alkyloxy, amino or lower alkylamino.
Rigterink disclosed several methods for preparing the compounds but his preferred method comprised reacting a phosphorochloridate or phophorochloridothioate of Formula II ##STR2## with an alkali metal or tertiary amine salt of a halopyridinol having the formula R--O-alkali metal or R--OH tertiary amine. The disclosed methods are carried out in an inert organic liquid under anhydrous conditions. In each of the disclosed processes, an alkali metal chloride or the tertiary amine hydrochloride salt is produced as a reaction byproduct which is removed by filtration. The disclosure of U.S. Pat. No. 3,244,586 is incorporated herein by reference.
Other phosphorothioates and phenylphosphonothioates have been similarly prepared and used. See, for example, U.S. Pat. Nos. 4,007,197, and 4,147,866 both of which teach the reaction of an alkali metal phenate, pyridinate or pyrimidinate with an O,O-dialkylphosphorochloridothioate or O-alkyl phenylphosphonochloridothioate under alkaline conditions in a hydrocarbon or chlorinated hydrocarbon solvent reaction medium and in the presence of a co-catalyst mixture of a quarternary ammonium or phosphonium salt and a tertiary amine.
U.S. Pat. No. 3,928,370 teaches the preparation of dialkyl pyridylphosphates by the reaction of an alkali metal pyridinate and a dialkyl hydrogen phosphite in the presence of a liquid reaction medium and in the presence of a tertiary amine catalyst.
U.S. Pat. No. 4,814,448 teaches the preparation of phosphorothioates and phosphates by the reaction of an alkali metal or alkaline earth metal phenate, pyridinate or pyrimidinate with a phosphorochloridothioate or phosphorochloridate in an alkaline aqueous hydrocarbon or chlorinated hydrocarbon solvent system in the presence of a tertiary amine catalyst and a nonionic surfactant. U.S. Pat. No. 4,814,451 teaches a similar process but with the absence of hydrocarbon or chlorinated hydrocarbon solvent.
Many other commercially available phosphorothioates and phosphates prepared by the same general procedure as set forth above are listed in articles by O. Johnson in Chemical Week, pp. 10-46 (Jul. 26, 1972), and by E. E. Kenaga and W. E. Allison in the Bulletin of the Entomological Society of America, 15(2), pp. 85-148 (Jun. 1969) which also list the U.S. Patent Numbers of many of said compounds. These articles are incorporated herein by reference thereto.